1. Field of the Invention
The present invention relates to window assemblies, and, in particular, concerns a replaceable glazing for window assemblies in public transportation vehicles.
2. Description of the Related Art
In recent years, ground based motor vehicles with aerodynamic exteriors have become popular due, at least in part, to a desirable appearance. In addition to aerodynamic exteriors, flush fitting window assemblies have also contributed to an improved aerodynamic appearance of vehicles including public transportation vehicles, such as buses.
Typically, the glazing of flush fitting window assemblies is recessed within the sidewall of a vehicle so as to form an aerodynamic exterior surface. In most cases, conventional glazing is attached to a recessed periphery around the window opening using an adhesive material, such as glue, epoxy, or putty. The adhesive must be of sufficient strength such that the glazing remains secured in place during use of the vehicle.
In some circumstances, the glazing may need to be replaced due to vandalism, such as breakage, chipping, scratches, and fractures, and also for maintenance needs, such as seal replacement. Consequently, replacing conventional glazing often requires removal of the adhesive used to secure the glazing to the window opening.
In general, removing a high strength adhesive from a flush fitting window assembly is time consuming and labor intensive, wherein conventional glazing removal procedures may require more than one person to work a generally known glazing removal tool. For example, the glazing removal tool is forced through the adhesive between the glazing and the framing supports in the sidewall of the vehicle. Usually, one worker is outside the vehicle and another worker is inside the vehicle on either side of the glazing. The glazing removal tool is moved back and forth by the workers in a cutting motion and guided around the entire periphery of the glazing so as to break the mounting seal of the adhesive. This cutting procedure is time consuming because it has to be performed slowly so as to not damage the window opening.
Once the seal of the adhesive is peripherally broken and the glazing is detached from the window opening, the remaining adhesive on the window opening needs to be removed. Unfortunately, removing the adhesive may cause permanent damage to the framing supports of the window opening. Scrapping the adhesive with a scrapping tool may cause adverse wear on the framing support surfaces, which may result in the framing supports of the window assemblies not properly sealing with reattached glazing. Also, this procedure may cause chipping or flaking of the paint around the window opening resulting in an undesirable appearance. Moreover, the adhesive may need to be scrapped off using undesirable chemical distillates that may evaporate into unhealthy fumes in the work area.
Once the old adhesive is removed, adhesive is reapplied to the window framing and allowed to cure for a lengthy amount of time for proper adherence of the glazing to the window framing. Unfortunately, the curing procedure incurs additional processing time for glazing replacement. In some cases, pressure needs to be applied around the perimeter of the glazing during curing. Otherwise, the glazing may not seal correctly to the window framing. If too much pressure is applied during curing, then the glazing may fracture, or the frame may deform. If too little pressure is applied during curing, then air gaps may form between the glazing and the window framing resulting in a degraded seal. As a result, the process of gauging the pressure and monitoring the pressure distribution on the glazing surfaces even further increases the amount of processing time for glazing replacement.
Therefore, due to the time consuming procedures, conventional glazing and adhesive removal processes require an exorbitant amount of down time for the vehicle. In the case of public transportation vehicles, the vehicles cannot be used in their designed capacity during the above described conventional window replacement processes resulting in loss revenue for the vehicle owner. Also, the manner in which conventional glazing replacement processes are conducted may result in permanent damage to the window openings.
From the foregoing, it will be appreciated that there is a need for an improved window assembly that is easily removable and replaceable while still maintaining the aerodynamic appearance of flush fitting window assemblies for vehicles. To this end, there also exists a need for a window mounting assembly that allows for multiple detachments and reattachments of the glazing from the window assembly with less difficulty such that glazing replacement is less labor intensive and time consuming.